1. Field of the Invention
The present invention relates to a developing device provided with a removing member that removes residual nonmagnetic single-component developer from a developer-carrying member, and an image-forming device including the developing device.
2. Related Art
One type of developing device well known in the art includes a developer-carrying member that develops an electrostatic latent image formed on an image-carrying member by supplying a charged nonmagnetic single-component developer to the surface of the image-carrying member, and a supplying member that supplies developer to the developer-carrying member. In this type of developing device, an image formation is performed in an electrophotographic method. That is, the supplying member supplies a nonmagnetic single-component developer, such as toner, accommodated in a toner-accommodating chamber or the like to the developer-carrying member while tribocharging the developer. A thickness-regulating member, such as a blade or the like, regulates the developer at a uniform thin layer. When the developer reaches a position across from the image-carrying member, the developer carried on the developer-carrying member is selectively deposited on an electrostatic latent image formed on the image-carrying member. Then, the nonmagnetic single-component developer deposited on the image-carrying member is transferred onto a recording medium, such as a recording paper.
However, a problem caused by what is called sleeve ghosting can occur when some of the developer is not supplied to the image-carrying member for developing the electrostatic latent image and remains on the surface of the developer-carrying member after passing by the position opposing the image-carrying member. Thereupon, Japanese unexamined patent application publication No. HEI-9-236979 proposes to provide a removing member on the upstream side of the supplying member in the rotational direction of the developer-carrying member to remove the developer that is not supplied for developing the latent image but remains on the surface of the developer-carrying member. The occurrence of sleeve ghosting can be satisfactorily prevented in this case since the developer is supplied from the supplying member to the developer-carrying member after first removing the residual developer from the developer-carrying member.
However, in the device disclosed in Japanese unexamined patent application publication No. HEI-9-236979, the developer-carrying member is rotated so that the peripheral surface of the developer-carrying member opposing the supplying member moves from bottom to top in relation to the direction of gravity, while the removing member is rotated such that the peripheral surface of the removing member opposing the developer-carrying member moves from top to bottom. Further, the removing member is disposed at the bottom section of a developing cartridge. Accordingly, toner removed by the removing member collects in a space between the removing member and a bottom surface of an outer case of the developing cartridge, which can have an adverse effect on toner circulation. A worsening in toner circulation can lead to such problems as a drastic reduction in image quality in parts of the formed image.